Two types of computing methods, namely the floating point arithmetic and fixed point arithmetic are available in spreadsheet software. While computing, the floating point arithmetic is generally performed because the computing speed is faster as compared to the other type of arithmetic. If any column truncation occurs in the result of computing, the user switches to the fixed point arithmetic, whereby recovering the computing error that had occurred because the floating point arithmetic was executed.
In the conventional technology as described above, because the user manually switches the computing mode to the fixed point arithmetic and re-computes if a computing error due to column truncation is generated in a result of computing based on the floating point arithmetic, the recovery processing is rather inefficient and not convenient.
Also, in a case where a user switches the computing mode to the fixed point arithmetic fearing occurrence of column truncation error even if no computing error has been generated in the floating point arithmetic, the computing speed becomes disadvantageously lower.